BIOB11H3 Lecture Notes - Lecture 6: Isoleucine, Peptide, Organic Synthesis
Document Summary
Association of mrna with ribosomes & subsequent decoding & formation of a polypeptide chain. *proteins= 20 diff. amino acids (64 combinations, triplet code) A change in a single base nay cause an amino acid to be altered. In 1956, ingram sequences the peptides of hemoglobin and notices glu to val substitution. >reading frame change due to insertion or deletion. 3 or multiples of 3 restores reading frame. Lyse cells, centrifuge to remove membrane, molecular machinery is present. Add rna n i e t o r. >combined bacterial extract with synthetic mrna of poly u, poly a & poly c to form polypeptides. Brute force: statistical determination of triplet concentration in mixture. Organic synthesis could not be directed, but polymers with controlled ratios of different nucleotides could be made. Scientists could then analyze the amino acid content of the protein produced by this mixture to associate certain amino acids with information in codons.
